The Herpes viruses are responsible for a large number of human diseases. All Herpes viruses possess a proteinaceous layer termed tegument which lines the inner surface of the viral envelope. Correct assembly of tegument and envelope is essential for the production of an infectious virus particle, and thus for the progression of disease. However, little is known of how tegument proteins recognize and bind to specific cellular membranes, nor how they ensure their assembly into the maturing virion. This proposal will investigate membrane and tegument sorting information present within the Herpes simplex virus (HSV) tegument protein vhs. We will identify the cytoplasmic organelle which binds vhs, and determine the role of this association in the HSV life cycle. Sequences responsible for vhs/organelle binding will be identified, and we will determine which regions of vhs ensure incorporation of this protein into the mature virus. Information obtained from this study will help in the design of agents able to interfere with vhs assembly into the HSV particle, reducing the virulence of this serious human pathogen.